Week 39: The microscope

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 4

Microscopy

• What are the parts of the microscope
  
• How should you operate the microscope
  
• The drawings rules for microscope drawings 

learning goal

The biological drawing rules 

• white paper
• use a hb pencil
  
• make large drawings
• draw clean cut lines, do not sketch
• draw what you see
  
• fill in the drawing information (name, class, date, name of organism, enlargement, view)  
• label parts: with a ruler, a horizontal line, name on the right side of paper, behind the line 

How to make a waterweed specimen

What do you need:

• slide, 
• coverslip,
• tweezers,
• pipette,
• pencil

1. Take a slide and put a drop of water onto it.

2. Use the tweezers to pull off a leaf of waterweed and put it in the drop of water.

3. Slowly lower a coverslip on top of the waterweed in an angle.

www.bioplek.org

The pointing needle.

Bring what you want to view very close to the tip of the pointing needle! Focus!

03:19

Most of the rules in this video are the same as we discussed in class, but there are also some differences. State the differences you noticed.

The microscope

eyepiece lens = lens, magnifies 10x

tube = holds the eyepiece lens

revolver = holds the objective lenses, turns around

objective lenses = lenses hold by the revolver. Magnify 4x, 10x and 40x

stage = holds the slide

arm = used to hold the microscope when carrying

focus knob = lets you move the stage up and down. This helps you focus the image. There is a coarse and a fine knob. 

lamp = source of light

condensor = lets you control the amount of light passing through the slide

base = this is the base the microscope stands on

Through which part of the microscope do you look?

1. condensor
2. objective lens
3. eyepiece lens
4. revolver

revolver

objective lens

eyepiece lens

tube

turning piece that holds objective lenses

holds the eyepiece lens

lens, magnifies 10x

lens, magnifies 4x, 10x and 40x

What is the function of the condensor?

1. magnify the object
2. control amount of light
3. to hold the microscope
4. turn microscope on/off

Which part lets you focus the image?

What is the use of the objective lenses?

1. magnify image
2. control amount of light
3. move the object up and down
4. sturdiness

base

focus knob

condensor

stage

objective lens

tube

What are you no longer allowed to do once you switch form the red objective lens to one of the others?

1. make changes to the amount of light
2. turn the revolver
3. turn the coarse focus knob
4. turn the fine focus knob

What is part 2?

In what state should you hand in the microscope?

1. stage down, smallest objective lens above stage
2. stage up, smallest objective lens above stage
3. stage down, largest objective lens above stage
4. stage up, largest objective lens above stage

Make a plan of action on how to properly focus the microscope on your object. Take a picture of this list (on paper) and upload here

Summarise (on paper) the drawing rules for yourself and upload a picture of it below

We will have a microscope lesson soon.

You are allowed to use:

• your plan of action for focussing the microscope. 
• your summary of the drawing rules 
• a pencil, eraser and ruler.